1. Field of the Invention
The invention relates to a rotary electric machine terminal block provided on a transaxle case that contains a rotary electric machine. Particularly, the invention relates to a rotary electric machine terminal block whose size is reduced by adopting an insert molding process.
2. Description of the Related Art
There are generally known an electric motor vehicle propelled by electric power from a battery, a fuel cell motor vehicle propelled by electric power generated by a fuel cell, a hybrid motor vehicle propelled by a combination of an internal combustion engine and a rotary electric machine that functions as an electric motor or an electricity generator, etc. In these motor vehicles, electric power is supplied from a battery or the like to an electric motor under a control by an inverter for the purpose of propulsion of the motor vehicle. Furthermore, during braking, the battery is charged with regenerative electric power by causing an electric motor to function as an electricity generator. Besides, in the hybrid motor vehicle, if the state of charge of the battery becomes low, the battery can be charged by driving the electricity generator by using the internal combustion engine. Therefore, the hybrid motor vehicle does not require the battery charging operation which is essential to the electric motor vehicle, and actively uses the rotary electric machine that is an electric motor or an electricity generator.
In the hybrid motor vehicle, however, it is necessary to mount in limited spaces of the vehicle a battery as a vehicle propulsion electric power source, an inverter that supplies electric power from the battery to the rotary electric machine while controlling the electric power, a connection cable capable of feeding large current to the rotary electric machine, etc., in addition to substantially the same kinds of devices and the like as mounted in an ordinary engine-propelled motor vehicle. Therefore, size reduction of various appliances employed in the hybrid motor vehicle are being pursued more vigorously than in the engine-propelled motor vehicle. Besides, in the hybrid motor vehicle, since an engine, a rotary electric machine, a motive power distribution mechanism and a transmission mechanism are mounted as an integrated unit within a transaxle case (hereinafter, also referred to simply as “case”), the case is provided with a connector for connecting the rotary electric machine and the inverter.
In the hybrid motor vehicle, the voltage supplied to the rotary electric machine by the inverter is designed to be a high voltage of 500 volts or more, in order to improve the performance as an electric motor vehicle. Because of the use of such high voltage, it is necessary to provide a measure for reducing noise in high-voltage portions and a measure for preventing short-circuiting of the oil-cooled rotary electric machine, terminals and the like. Besides, the cable that connects the rotary electric machine and the inverter needs to be securely fixed to the case or the vehicle body in order to withstand vibration from the rotary electric machine or the cable. Therefore, for the cable that supplies high voltage, optimization of the shield coating, the water-proof coating, the cable layout and the method of fixation of the cable is pursued. The three-phase alternating-current power lines connected to the rotary electric machine are connected to a terminal block while a predetermined creepage distance is secured. Furthermore, a shield cover is provided to reduce the radiation of electromagnetic noise from the terminal block.
In particular, the terminal block, the cable connected to the terminal block, etc. are exposed to vibration that occurs during the traveling of the vehicle, and therefore need anti-vibration measures. Therefore, Japanese Patent Application Publication No. 2005-235443 (JP-A-2005-235443) describes a fixation structure for a connector which is capable of absorbing vibration from a cable. This connector fixation structure is provided for the connection between a first connector provided on a vehicle-mounted case that houses a rotary electric machine and the like, and a second connector provided on a cable that is to be connected to the first connector. More specifically, the connector fixation structure is provided for fixing the second connector. Besides, in this connector fixation structure, the cable is fixed by using a clamp that absorbs vibration from the cable. However, the first and second connectors described in JP-A-2005-235443 are electric power supply line connectors. In this case, it is necessary that connectors for signals from rotation angle sensors needed for the control of the rotary electric machine and signals for the measurement of the coil temperature of the stator be provided separately from the first and second connectors, and it is difficult to secure a space in which to mount the connectors of the power supply lines and the signal lines.
As a construction for overcoming this problem, Japanese Patent Application Publication No. 2008-301544 (JP-A-2008-301544) describes a rotary electric machine terminal block that is a composite connector combining a connector for supplying electric power and a connector for a sensor. FIG. 18 shows a rotary electric machine terminal block 150, and FIG. 19 shows an exploded view of the rotary electric machine terminal block 150 shown in FIG. 18, and FIG. 20 shows a sectional view of the rotary electric machine terminal block 150. In FIG. 18, the rotary electric machine terminal block 150 is provided on a transaxle case that contains an engine unit 250, an electricity generator unit 260 connected to a power splitting mechanism, and an electric motor unit 270 that generates drive force. As shown in FIG. 19, the rotary electric machine terminal block 150 connects a rotary electric machine of the electricity generator unit 260 and an electric power bus cable 141 via an electric power bus cable connector 143. Besides, a signal cable 116 for signals related to the rotation angle of the rotary electric machine and the like is connected to a signal line connector 113.
As shown in FIG. 19, in the rotary electric machine terminal block 150, a composite connector 110 having an electric power line connector 111 covered with a shield shell 112, the signal line connector 113 and a face seal member 118 is held to the electricity generator unit 260 by a plate 114 from above so that an opening of the electricity generator unit 260 is closed. As shown in FIG. 20, the opening of the electricity generator unit 260 is used to connect the electric power line connector 111 and the signal line connector 113 to the rotary electric machine. An edge of the opening is sealed with the face seal member 118 and the composite connector 110 is pressed to the electricity generator unit 260 by the plate 114 and plate-fastening screws 147 shown in FIG. 18 so that the opening of the electricity generator unit 260 is tightly closed.
Furthermore, as shown in FIG. 19, the electric power bus cable 141 extending along the electricity generator unit 260 is connected by the electric power bus cable connector 143 to the electric power line connector 111 of the rotary electric machine terminal block 150 (in the direction B in FIG. 19), and the terminal of the U, V and W-phase electric power bus cable 141 is fixed in a direction perpendicular to the electricity generator unit 260 (in the direction C in FIG. 19) by the plate-fastening screws 147. A water-proof seal cap 121 is fitted to the terminal. Besides, as shown in FIGS. 18 and 19, the electric power bus cable connector 143 is fixed to the electricity generator unit 260 by a cable stay 142 and cable stay screws 145, and the cable stay 142 and the shield shell 112 are fixed to each other by shield shell screws 146. Thus, in the related art, the composite connector 110 provided with the electric power line connector 111 and the signal line connector 113 is constructed.
However, the rotary electric machine terminal block 150 described in Japanese Patent Application Publication No. 2008-301544 (JP-A-2008-301544) is a die-cast component part made of a resin and aluminum, and is therefore inferior in strength to the case. Therefore, it sometimes happens that unpleasant sound or vibration from gears propagates to the rotary electric machine terminal block 150 via the case and therefore the plate 114 surrounding the composite connector 110 resonates. In order to prevent this resonance, it is conceivable to attach a reinforcement member for enhancing the strength of the plate. However, in such a case, the size of the composite connector 110 becomes large so that the composite connector 110 may interfere with another appliance and may not be able to be mounted. Besides, if the plate 114 and the composite connector 110 are provided as separate members, the mounting operation becomes complicated. Therefore, it is necessary to integrate the plate 114 and the composite connector 110 through the use of screws or the like, which makes it difficult to reduce the number of component parts.